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J l /J4 United States Patent 3,161,735 ELECTRIC DISCGNNECT SWITCH WalterKowalski, South Milwaukee, Wis., assignor to McGraw-Edison Company,Milwaukee, Wis., a corporation of Delaware Filed May 25, 1961, Ser. No.112,561 6 Claims. (Cl. 20048) This invention relates to electricswitches and, more particularly, to hook stick operated air breakdisconnect switches.

In the servicing of certain high voltage electrical apparatus such ascircuit breakers, the preferred safety practice is to disconnect theapparatus from the energy source by means of a visible air gap devicesuch as a disconnect switch so that it may be visually determined thatthe device is de-energized and that servicing may proceed in safety.Such disconnect switches are generally mounted in an overhead locationand include costly operating mechanisms so that they may be operatedfrom ground level. Prior art hook stick operated disconnect switcheswere not employed in such installations because their method ofoperation would require the operator to be located above and to the rearof the switch blade.

It is an object of the invention to provide a hook stick operateddisconnect switch which may be operated from below when it is mounted ina horizontal position.

Another object of the invention is to provide a hook stick operateddisconnect switch which is latched in each of its opened and closedpositions.

Another object of the invention is to provide a disconnect switch havingaugularly adjustable stationary contacts which allows the supportingstructure of the switch blade and the stationary contacts to be locatedin different planes.

These and other objects and advantages of the instant invention willbecome more apparent from a detailed description of the preferredembodiment thereof taken with the accompanying drawings in which:

FIG. 1 shows a hook stick operated disconnect switch according to apreferred embodiment of the instant invention employed with electricalapparatus being energized from a bus bar system;

FIG. 2 is a side elevational view of the device shown in FIG. 1;

FIGS. 3 and 4 illustrate the mechanism for latching the switch blade inits open position; and

FIG. 5 shows the stationary contact assembly and means for its angularadjustment and the latch assembly for holding the switch blade in itsclosed position.

In general terms, the invention comprises a horizontally mounteddisconnect switch having an operating lever pivotally mountedintermediate the ends of the switch blade and disposed in asubstantially vertical direction, linkage means interconnecting theupper end of the operating lever and a latching member normally holdingthe switch blade in its connected position so that the application of aforce to the lower end of the operating lever by means of a hook stickor the like will move the latching member out of engagement with theswitch blade and allow the blade to be pivoted to its disconnectedposition.

According to a more specific aspect of the invention, a second latchingmeans is disposed at the hinged ends of the switch blade and is adaptedto latch the switch blade in its disconnected position. A second linkagemeans also interconnects the upperend of the operating lever to thesecond latching means so that pivotal movement of the operating leverunder the influence of a hook stick will release the second latchingmeans and allow the switch blade to be rotated to its connectedposition.

Referring now to the drawings in greater detail, FIGS. 1 and 2 show ahook stick operated air disconnect switch 3,161,735 Patented Dec. 15,1964 incorporating the instant invention and designated generally by thereference numeral 10. The switch 10 is illustrated connecting anelectrical device 11, such as a circuit breaker, to a supply bus 39. Theswitch 10 includes a first terminal member 12 for pivotally supporting aswitch blade 16 and which is shown in the illustrated application to beelectrically connected to the bus bar 39 and mounted atop a bus barsupport insulator 1.3. A second terminal member 14 is mounted atop oneof the bushings 15 of the device 11 and supports a stationary contactassembly 18.

As seen more specifically in FIGS. 3 and 4, the terminal 14 carries aU-shaped hinge member 20 having spaced vertical legs 21. A hinge clamp23 is releasably atfixed to the hinge end of the blade 16 by bolts 27and nuts 29 and has a pair of depending arms 24 for pivotal connectionto the legs 21 by hinge pins 26 which extend through aligned openings ineach. The pins 26 each engage a boss 25 integral with its correspondingarm 24 and each is held in place by a nut 28- received on its threadedend. An arm 30, extending laterally from the clamp 23, receives one endof a coiled counterbalance spring 31 whose other end is afiixed to thehinge member 20 through an arm 32 integral with an adjusting wheel 33which is held between one of the nuts 28 and the member 20.

The stationary contact structure 18, which is shown in greater detail inFIG. 5, comprises pairs of laterally spaced contact fingers 34 securedat their lower ends to the terminal 14 for receiving therebetween thefree end of the switch blade 16 in very high pressure electricalengagement. To enhance contact pressure between the contact fingers 34and the switch blade 16, leaf springs 35 are disposed against the outersurface of each of the contact fingers 24 and are loaded by retainingpins 36 carried by a tie bar 38 extending laterally through the fingers34 and the springs 35. It can be seen that the reaction between theretaining pins 36 and the springs 35 will hold the contact fingers 34 inhigh pressure engagement with the end of the switch blade 16 when thelatter is in its closed position shown in FIGS. 2 and 5.

Referring specifically now to FIG. 5, the bushing 15 includes aconductive stud 42 extending from its upper end and upon which ismounted an adapter assembly 44 for supporting the teminal 14. Theadapter 44 includes a U-shaped base member 45 atfixed by nuts 46 to theconductive stud 42 and having a pair of vertical arm portions 48. Inaddition, the adapter 44 includes a mounting member 49 which is alsosubstantially U-shaped and has a pair of depending leg portions 50 whichslidably engage the outer surface of the arms 48. A pair of bolts 51,secured by nuts 52 (only one of which is seen in FIG. 5), extend throughaligned apertures in each pair of adjacent portions 48 and 50 on eachside of assembly to pivotally support the mounting member 49 on the basemember 45. A pair of arc-shaped apertures 54 are formed in each of thelegs of the mounting member 50 equidistant-1y from the axis of the bolts51 and extending in a generally vertical direction. In addition, a pairof similar arc-shaped apertures 55 are formed in each of the arms of thebase of member 45 and each are in register with the correspondingapertures 54 in the legs 50 when the members 45 and 49 are substantiallyparallel. The center of curvature of each of the apertures 54 and 55 iscoincident with the axis of bolts 51 so that relative rotation ofmembers 45 and 49 will move said apertures in parallel circular paths. Abolt 56 extends through each pair of corresponding apertures 54 and 55and each is secured by a nut 56 which engages the inner surface of arms48 to provide a good mechanical and electrical connection between themembers 45 and 49. Because the apertures 54 and 55 have the same radiusof curvature and are equidistant from the bolts 51, member 49 can berotated through a plurality of angular position relative to the basemember 45 and may be secured in any of these positions by means of thenuts 54. As seen in FIG. 1, therefore, alignment between the switchblade 16 and the stationary contact assembly 18 can be achieved eventhough the terminal member 12 is a substantial vertical distance aboveor below the terminal member 14. Also, as seen in FIG. 5, the adapterassembly 44 allows the switch blade 16 to properly engage each of thecontact fingers 34 regardless of the angle it makes with the stud 42.

It will be appreciated that if the stationary contact assembly 18 isdisplaced vertically relative to the terminal member 12, as seen in FIG.1, for example, the length of the switch blade 16 will have to beincreased if it is to mate properly with said contact assembly. Theeffective length ofthe switch blade may be modified for this purpose byloosening the bolts 27 which secure :the clamp 23. The blade 16 is thenmoved inwardly or outwardly relative to the terminal 12 and the clamp 23is resecured.

As illustrated in FIGS. 1, 2 and 5, a latching assembly by a sear spring85 for rotation in a counterclockwise direction about a pivot pin 86extending between the arms of a Ushaped bracket member 87 mountedbetween the legs 21 of the hinge member 20.

A bifurcated latch release lever 88 is rockably mounted on the pin 86and carries a pair of projecting latch engaging portions 96 adjacenteach of the latch arms 84. The other end of the latch release lever 38is pivotally connected at 91 to a pair of link members 92 whose otherends are pivotally connected through an adjusting link 94 to theoperating lever '70 at 74.

The link 94 has a slot 95 for adjustable connection to the end of thelinks 92 by a bolt and nut 96. This allows 66 is provided for securingthe switch blade 16 in its connected position relative to the stationarycontact 18. The assembly 69 includes a pair of parallel latch arms 61(only one of which can be seen in FIG. 5) pivotally mounted on a pin 62extending between the arms of a U-shaped bracket 63 aflixed to theterminal 14. A sear spring 66 surrounds pivot pin 62 and engages theterminal 14 and the latch arms 61 thereby urging said arms for clockwiserotation, as viewed in FIG. 5, into engagement with a latch pin 67extending laterally through the tip of the switch blade 16. Thislatching engagement between the latch arms 61 and the pin 67 preventsunintended movement of the switch blade 16 out of its connected positiondue to the magnetic forces of short circuit currents and the like.

A latch release lever 68 is pivotally mounted near its lower end on thelatch pin 67 and has a pair of latch release projections 69 on its lowerend which engage the arms 61. An operating handle 76 is shown in FIG. 2to be pivotally mounted intermediate its ends on the switch blade 16 ata point 71 between the terminals 12 and 14. A pair of parallel links 72are pivotally connected at 73 to the upper end of latch release arm 68and at 74 to the upper end of the operating handle 70. It can be seen,therefore, that rotation of the operating handle 7 0 through a slightcounterclockwise angle, by means of a hook stick inserted into the pullring 75, will rock the latch release lever 68 clockwise from its fullposition in FIG. 5 to its position shown by phantom lines wherein thelatch release projections 69 will engage the latch arms 62 and rotatethem counterclockwise to their phantom position against the influence ofspring 66. As a result, the latch arm 62 will move out of latchingengagement with the pin 67 so that switch blade 16 will be free forpivotal movement to its open position. Rotation of the latch releaselever 68 is limited by a pin 64 extending through the tip of switchblade 16 adjacent the latch pin 67 and which lies in the path of theopposite sides of an arcuate slot 65 in the edge of the lever 68.

When the switch blade 16 reaches its fully opened position, a lug 76extending integrally from the boss (as seen in FIGS. 2 and 3) engages anadjustable stop 77 threadably received in a T-shaped bracket '78 whichis secured to the hinge member 26 by mounting bolts 79 which also holdsaid hinge member to the terminal 12. In addition, the switch blade 16is held in this position against accidental reclosing due to vibrations,jarring or the like by a latch assembly 81. The latch assembly 81 issimilar to the assembly 64 which latches the blade 16 in its closedposition and includes a latchpin 82 extending transversely between lugs83 integral with the legs 24 of clamp 23. Pin 82 is engageable by a pairof latching arms 84 identical to the latch arms 62 and which are urgedthe effective distance between the points 74 and 91 to be changed tocorrespond to changes in the effective length of the switch blade 16 asdiscussed hereinabove.

When the switch is latched in its open position shown by the phantomlines in FIG. 1, release of the latch assembly 81 is accomplished byrotating the operating handle 70 in a counterclockwise direction. Asshown in FIG. 4, this moves the link 92 and the latch release lever 88from their full position to their phantom position whereupon the latchrelease projections 90 will engage the latch arms 84 to rotate them outof latching engagement with the pin 82. As a result, the switch blade 16is free for counterclockwise rotation from its phantom position asviewed in FIG. 1 to its connected position shown by full lines.

It can be seen from the foregoing that the invention provides for usewith encased electrical apparatus, such as circuit breakers, adisconnect switch which is operable by means of a hook stick from groundlevel thereby eliminating expensive operating mechanisms required byprior art installations wherein rotating insulator type disconnectswitches were employed. In addition, the invention provides an airdisconnect switch wherein the circuit breaker bushing and bus barstructure may be employed for supporting the fixed contacts and switchblade respectively thereby eliminating costly switch supportingstructure. This is possible because the air break switch is hook stickoperated thereby eliminating the necessity for rotating insulatorsupport structure;

While only a single embodiment of the instant invention has been shownand described, it is' not intended that the invention be limitedthereby, but only by the scope of the appended claims.

I claim:

1. In an electric switch, a pair of terminals having a generallyhorizontal spaced relation, stationary contact means mounted on one ofsaid terminals, a switch blade mounted on the other of said terminalsand pivotal in one direction out of engagement with said stationarycontact means, latch means mounted adjacent said stationary contactmeans and having a member pivotally mounted for movement into and out oflatching engagement with said switch blade when the latter is in itsconnected position, an operating lever pivotally mounted intermediateits ends on said switch blade and extending in a substantially verticaldirection and having hook engaging means at its lower end, link meanscoupling the upper portion of said lever to said 'member, pivotalmovement of said lever in said one direction being operative to movesaid member out of latching engagement with said switch blade and topivot said switch blade to its disengaged position, pivotal movement ofsaid lever in an opposite direction being operative to pivot saidSwitchblade into engagement with said stationary contact means and topivot said member into latching engagement with said switchblade.

2. In an electric switch, a pair of terminals having a generallyhorizontal spaced relation, stationary contact means mounted on one ofsaid terminals, a switch blade mounted on the other of said terminalsand pivotal in one direction out of engagement with respect to saidstationary contact means, a latch member pivotally mounted adjacent saidstationary contact means and resiliently urged into latching engagementwith said switch blade when the latter is in its connected position, alatch release arm pivotally mounted adjacent said latch member andoperable upon pivotal movement in a first direction to move said latchmember away from said switch blade, an operating lever pivotally mountedintermediate its ends on said switch blade and extending substantiallyvertically and having hook engaging means at its lower end, and linkmeans connecting said operating lever to said latch release arm, pivotalmovement of said operating lever in said one direction being operativeto pivot said latch release arm in said first direction and to pivotsaid Switchblade in said one direction out of engagement with saidstationary contact means and into a nominally vertical position, pivotalmovement of said operating lever in an opposite direction beingoperative to pivot said switchblade into engagement with said stationarycontact means and to release said latch member for pivotal movement intolatching engagement with said switchblade.

3. In an electric switch, a pair of terminals having a generallyhorizontal spaced relation, stationary contact means mounted on one ofsaid terminals, a switch blade mounted on the other of said terminalsand pivotal in one direction out of a connected position and into anominally vertical disconnected position with respect to said stationarycontact means, a first latch means mounted adjacent said stationarycontact means for holding said switch blade in its connected position, asecond latch means on the other of said terminals for holding saidswitch blade in its disconnected position, an operating lever pivotallymounted intermediate its ends on said switch blade and extendingtransversely thereto for pivoting said switch blade between itsconnected and disconnected positions, and link means connecting saidlever and each of said first and second latch means so that theswiveling of said lever will move said first and second latch means in aswitch blade releasing direction.

4. In an electric switch, a pair of terminals having a generallyhorizontal spaced relation, stationary contact means mounted on one ofsaid terminals, a switch blade mounted on the other of said terminalsand pivotal into and out of connected and disconnected positions withrespect to said stationary contact means, a first latch member pivotallymounted adjacent said stationary contact means and resiliently urgedinto latching engagement with said switch blade when the latter is inits connected position, a first latch release arm pivotally mountedadjacent said latch member and operable to move said latch member awayfrom said switch blade, at second latch member pivotally mounted on theother of said terminals and resiliently urged into latching engagementwith said switch blade when the latter is in its disconnected position,a second latch release arm pivotally mounted adjacent said second latchmember and operable to move said second latch member away from saidswitch blade, an operating lever pivotally mounted intermediate its endson said switch blade and extending transversely thereto for moving saidswitch blade to its disconnected position, and link means connectingsaid operating lever to said first and second latch release arms,whereby said switch blade may be unlatched and moved into and out of itscor nected position by the application of a force to the lower end ofsaid operating lever.

5. In an electric switch having a pair of generally horizontally spacedterminals, stationary contact means mounted on one of said terminals, aswitch blade mounted on the other of said terminals and pivotal in onedirection out of engagement with said stationary contact means and intoa nominally vertical disengaged position, first latch mens for holdingsaid switch blade in its engaged position and second latch means forholding said switchblade in its disengaged position, operating meanspivotally mounted on said switch blade and extending generally downwardtherefrom, and link means coupling said operating means to said latchmeans, pivotal movement of said operating means in said one directionbeing operative to unlatch said first latch means and to move saidswitch blade to its disengaged position and to latch said second iatchmeans, pivotal movement of said operating member in an oppositedirection being operative to unlatch said second latch means and pivotsaid Switchblade into engagement with said stationary contact means andto latch said first latch means.

6. In an electric switch having a pair of generally horizontally spacedterminals, stationary contact means mounted on one of said terminals, aswitch blade mounted on the other of said terminals and pivotal out ofengagement with said stationary contact means and into a nominallyvertical disengaged position, first latch means mounted adjacent saidfixed contact means for holding said switch blade in its connectedposition and second latch means mounted on the other of said terminalsfor holding said Switchblade in its disengaged position, an operatinglever pivotally mounted on said switch blade intermediate its ends andextending transversely thereto in a generally vertical direction andhaving hook engaging means at its lower end, and link meansinterconnecting the upper portion of said lever and each of said latchmeans, pivotal movement of said operating lever in a first directionunlatching said first latch means and pivoting said Switchblade to itsdisconnected position and latching said second latch means, pivotalmovement of said operating lever in an opposite direction unlatchingsaid second latch means pivoting said switchblade into engagement withsaid stationary contact means and latching said first latch means.

References Cited in the file of this patent UNITED STATES PATENTS1,935,111 Christensen et a1 Nov. 14, 1933 1,979,852 Austin Nov. 6, 19342,246,072 Scott June 17, 1941 2,251,115 Crabbs June 29, 1941

1. IN AN ELECTRIC SWITCH, A PAIR OF TERMINALS HAVING A GENERALLYHORIZONTAL SPACED RELATION, STATIONARY CONTACT MEANS MOUNTED ON ONE OFSAID TERMINALS, A SWITCH BLADE MOUNTED ON THE OTHER OF SAID TERMINALSAND PIVOTAL IN ONE DIRECTION OUT OF ENGAGEMENT WITH SAID STATIONARYCONTACT MEANS, LATCH MEANS MOUNTED ADJACENT SAID STATIONARY CONTACTMEANS AND HAVING A MEMBER PIVOTALLY MOUNTED FOR MOVEMENT INTO AND OUT OFLATCHING ENGAGEMENT WITH SAID SWITCH BLADE WHEN THE LATTER IS IN ITSCONNECTED POSITION, AN OPERATING LEVER PIVOTALLY MOUNTED INTERMEDIATEITS ENDS ON SAID SWITCH BLADE AND EXTENDING IN A SUBSTANTIALLY VERTICALDIRECTION AND HAVING HOOK ENGAGING MEANS AT ITS LOWER END, LINK MEANSCOUPLING THE UPPER PORTION OF SAID LEVER TO SAID MEMBER, PIVOTALMOVEMENT OF SAID LEVER IN SAID ONE DIRECTION BEING OPERATIVE TO MOVESAID MEMBER OUT OF LATCHING ENGAGEMENT WITH SAID SWITCH BLADE AND TOPIVOT SAID SWITCH BLADE TO ITS DISENGAGED POSITION, PIVOTAL MOVEMENT OFSAID LEVER IN AN OPPOSITE DIRECTION BEING OPERATIVE TO PIVOT SAIDSWITCHBLADE INTO ENGAGEMENT WITH SAID STATIONARY CONTACT MEANS AND TOPIVOT SAID MEMBER INTO LATCHING ENGAGEMENT WITH SAID SWITCHBLADE.